Zodarion styliferum, a species of ant-eating spider, makes the little igloo-shaped rock nests pictured above to protect juvenile spiders. However, the nests fail to protect baby spiders from attacks by Calymmochilus dispar and Gelis apterus, two wasp species that hunt ant-eating spiders.

The nests are usually attached to larger rocks or dead wood. Researchers have discovered that the wasps attack the stone nests during the day when the spiders are inactive. The female waps (pictured below) have long olipositors (egg laying organ), which enables them to penetrate the walls of the spider nest and deposit eggs. The wasp larvae later feed on the spiders.

Dr. Stanislav Korenko from the Department of Agroecology and Biometeorology of the Czech University of Life Sciences, said in a statement, "Several groups of Hymenoptera develop on spider hosts feeding on the flesh of the spider or on its eggs. The parasitoids attack a number of spiders ranging from ground dwelling and fast moving hunters like wolf spiders to web spiders such as orb-web weavers that stay on webs during most of their life."